In a medium bowl whisk together the baking soda and cornstarch so there are no clumps.
Slowly add in the water and whisk together.
Pour into foil lined muffin cups and fill each one about half full so you get 6 muffin cups total.
Bake at 350 degrees F for 20 minutes.
Allow to cool completely and then remove foil liners.
Add 4-5 drops of essential oils of your choice to the top of each shower disc. Some recommendations include: Lavender, Peace & Calming or Cedarwood for restful nights, Citrus Fresh, Orange or Lemon for energizing mornings or Eucalyptus, Thieves and Peppermint for nasal discomforts.
Store in an airtight container.
To use place one shower disc on the floor of the shower and allow the water to run over it which will release the vapors of the oils in the disc.